The present invention relates to therapeutic devices and, more particularly, to dynamic systems that apply variable forces on the hand for therapy or rehabilitation.
Many injuries, diseases and neurological disorders affect the hand or digits, for example, by deforming the hand or digits, by decreasing the range of motion of the hand or digits, or by inhibiting muscular, structural or neurological function of the hand or digits. Individuals afflicted with such conditions often experience pain, discomfort, inhibited hand or digit function, and undesired attention when their hand or digits are deformed by such conditions. Moreover, diseases or injuries affecting the hand typically create a disability that is far more limiting than afflictions of other body parts.
Accordingly, a number of rigid, passive force splints have been developed to address these conditions. An example of a conventional hand splint is found in U.S. Pat. No. 4,949,711 to Gyovai, which discloses an outrigger including a pulley system, mounted to a rigid plastic splint that encapsulates the hand and wrist. Finger slings are positioned on each finger, and rigging is strung from the slings, over the pulley system, toward the wrist. The wrist end of the rigging is attached to the splint with a touch fastening system, which, when adjusted reconfigures the fingers by extending only the metacarpal phalangeal joint.
Although conventional hand splints like the one in Gyovai provide some relief, they are bulky, awkward and tend to draw unwanted attention to the hand and wearer. Frequently, the sheer size of the outrigger structure makes it impractical to wear the hand splint when engaging in everyday activities. Furthermore, because the hand splint is rigid, other portions of the hand cannot be adjusted when the splint is worn. Moreover, it is possible for the outrigger and/or rigging to “catch” on items, which creates a safety hazard for the wearer. These stated issues decrease the wearing compliance of rigid splints. Additionally, given the relatively fixed spatial configuration of the pulley systems, such hand splints typically are incapable of reforming the fingers except along very specific, single lines of force. Thus, the functionality of the hand is markedly diminished.